52 STORRS AGRICULTURAL EXPERIMENT STATION. 



rapidly though they remained in larger numbers at the end. 

 The last analyses of the iced milk showed the presence of 15 

 per cent, of these streptococci, while in the non-iced milk they 

 had become reduced to less than one-half of i per cent. 



7. The icing had apparently no influence upon the lique- 

 fiers, which were present in small proportions only in all the 

 experiments. 



8. It will be noticed that in the earlier tests there was a 

 very large percentage of undetermined organisms. The reason 

 for this appears to be in part because of the large numbers of 

 streptococci. These organisms produce a slight alkaline reac- 

 tion and when present in numbers neutralize the acid which is 

 developed by the conuiion lactic bacteria. In the first plate of 

 the non-iced milk the presence of these alkaline colonies ob- 

 scured the development of the lactic bacteria so that they could 

 not be differentiated. The result was that nearly half of the 

 colonies in this plate could not be determined; most of them 

 were probably streptococci and the rest probably one of the 

 lactic bacteria. It will be seen further that as the acid organ- 

 isms increased in number the difficulty of separating them 

 from the streptococci decreased and, finally, in the later plates 

 all of the colonies were easily differentiated. 



Experiment No. p. Noveviber. — This experiment was prac- 

 tically a repetition of the last. The results were closely in 

 accordance with those of the previous experiment. The fol- 

 lowing tables give the results. 



